Bridge.



N0. 828,873. vPATENTED AUG. 21, 1906.

F. G. BORG.

BRIDGE.

APPLICATION FILED runs, was.

2 SHEETS-SHEET 1.

PATENTED AUG. 21, 1906. F. G. BORG.

BRIDGE.

APPLIOATION FILED FEB. 5, 1906.

2 SHEETS-SHEET 2.

FREDRIKG'; BORG, OF CHICAGO, ILLINOIS.

BRIDGE Specification of Letters Patent.

Patented Aug. 21, 1906.

Application filed February 5, 1906. Serial No. 299,414.

To all whom it may concern:

Be it known that I, FREDRIK G. Bono,-a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Bridges, of which the following is a specification.

This invention relates to bridges, and relates particularly to bascnle-bridges.

Primary Objects of the invention are to providea counterweight applied to the bridgespan in such manner that it will exactly counterbalance said bridge-span in all positions: to provide a counterbalance in which the counterweight is applied to the bridge-span in such manner that said counterweight and its connections to said bridge-span will be i above its point of application to said bridge- 1 span in all positions, thereby rendering unnecessary apit below said bridge to, receive said counter. 'eight and its connections, and to provide improved means for pivotally supporting said bridge-span whereby the supports for said bridge-span may be located entirely outside thereof, thus providing for bracing said bridge-span laterally throughout its length.

T 0 effect these ends, myinvention consists of the various features, combinations of features, and details of construction hereinafter described and claimed.

In the accompanying drawings, in which my invention is fully illustrated, Figures 1, 2, and 3 are side views of bascule-bridges, illustrating different ways of applying the counterweights thereto to effect the objects of my invention, said bridges being shown in open position in dotted-lines, together with the counterweights and their connections to the bridge-spans in positions corresponding thereto; and Figs. 4 and 5 are partial sectional views on the ,line' w a? of Figs. 1, 2, and 3, showing different ways of pivoting the bridgespan.

Referring now to the drawings, A designates the spans of bascule-lwidges, which as regards their usual features may be of any desired or approved construction.

The bridge-spans A are pivotally supported on suitable piers orcolumns B by means of trunnions C, and as regards my im roved counterbalance the manner of pivotal y supporting said bridge-spans is immaterial.

To effect the objects of my invention, as it relates to laterally bracing the bridge-spans throughout their entire lengths, the piers or columns which support said bridge-spans are l located entirely outside of said'bridge-spans, 1 thus providing unobstructed spaces between 5 said piers or columns and providing for the i use of spans braced laterally throughout their lengths in the desired manner. This object of my invention may be effected in two difl ferent ways, which I will now describe.

As shown in Fig. 4, trunnions C are revolubly mounted in a suitable bearing formed in the columns B and are secured against rotation in a suitable bearing on the bridgespan, requisite stiffness and rigidity being imparted to said trunnions by means of ex- 5 tensions 0 thereof, the remote ends of which I are secured in a suitable bearing 0, secured to the bridge-s an at a distance from the .main trunnionearings therein.

As shown in Fig. 5, the trunnions C are secured against rotation in suitable hearings in the columns B and in piers or columns B, lo? cated outside thereof, the inner ends of said trunnions C projecting inwardly and engaging suitable bearings on the brid e-span, so that said bridge-span will turn free y thereon.

As less strength is reglnired in the trunnions C at points remote cm the main bearings, the projecting ends 0 thereof may be tapered, as shown, for the purpose of saving stock.

I will now describe my invention as it relates to means for counterbalancing the same.

Broadly stated, my invention consists of a counterweight a plied to the bridge-span through the me ium of a compound lever comprising members dpivotally connected, respectively, to a fixe support and to the shore endof the bridge-span at one end and to each other at their other ends, the relation being such that said lever members will be substantially parallel, respectively, to right lines, passing through the axis of the bridgespan trunnions and the points of pivotal attachment of the said lever members to said fixed support and bridge-span.

What I now consider the preferable embodiment of my invention is that shown in Fig. 1 of the drawings, referring to which D designates as a whole a compound lever 1 is pivoted at a point 3 diagonally above the bridge-trunnion C to a suitable fixed support consisting, as shown, of an upward extension 4 of the bridge-span-sup orting pier or column B. The lever mem er 2 is pivoted at5 comprising members 1 and 2. The member.

ably on a line passing through the axis ofthe trunnions and the center of. gravity of the bridge-span. The opposite ends of the lever member 1 and the.

column B extends rearwardly there members 1 and 2am pivotall connected to each other at 6, the relative engths of said.

lever members being such that they will be substantially parallel the.member 1 with a right line passing through the pivot-point 5 of the member 2 and the axis of the bridgetrunnions and the member 2 with a right line passing through the pivot-point 3 of the axis of said bridge-trunnions.

The counterweight 7 is pivotally connected at 8 to a carriage-9, which is movable along suitable guides formed on an upright support 10, and said counterweight is con nected with the membe'rl of the compound lever D by means of a strut 1 1, the lower end of which is pivotally connected to said lever member 1" at any desired point, as shown at a point outside of the po1nt 6, at which the lever members'l and 2 are pivoted to each other. My invention, however, contemplates pivoting said strut 11 to said lever member 1 either at or inside of the point 6, at which said lever members 1 and 2 are pivoted to each other. I i

The counterbalance shown in Fig. 2 compri's'es'substantially the same elements as the counterbalance shown in Fig. 1to Wit, the bridge span A, 'supportedupon the iers or columns B by means of trunnions C, t e compound lever D comprising the lever members 1 and 2, pivotally connected to each other 'a'tgfi at one end, and at their other ends, re-

spectively, to the upward extension 4 of the supporting pier or column B and to the shore end of the bridge-span. As shown in Fig. 2, the counterwei ht 7 is secured directly to the outer end 0 the lever member 1, so that in operation it moves in'the are of a circle. Also owing to the different form of bridgespan'A the upward extension 4- of the fpier or om a greater distance. than in Fig. 1 to provide sufficient 'roornifo l the bridge-s an A to open. As shown", al'so,..the upper en of said extension 4' is supported by an additional column B thus imparting requisite strength and stability to the structure.

The counterbalance shown in Fig. 3 likewise comprises substantially the same elements as'are shown in Figs. 1 and 2'ftowit, the bridge-s an A, supported upon thepiers or columns B by the trunnions C, the-compound lever 1), comprising the members 1 and 2 pivotally connected to each other at 6 at one end," and at their other ends, respectively, to the upward extension 4 of the piers or columns B and to 'theshore end of the bridge-s an A, and, the counterweight 7 applied to t e lever-member 1 As shown one end and to the lever member 1 at its opposite end. I

My invention contemplates the use; either of separate counterweights 7 7 7 applied to pivotally connected to said counterweight at I the bridge. one at each side of the roadway by means of the described connections or a single counterweight which extends across and above the roadway and provided with the described connections to the bridge-span at both ends.

Any desired or approved means may lee-employed for opening and closing the bridge as, for instance, a pinion 12, driven by means of suitable driving connection with any suitable motor and which engages a segmental gear 13- on the bridge-span in the usual man'- ner, as indicated in Figs. 2 and 3, or, as ind-L cated in Fig. 1, by means of a gear 14, revolubly mounted on the carriage 9, to which the counterweight 7 is connected, which engages a rack 15 on the standard 10 and to which rotation is adapted to be imparted by means of driving connection with any suitable source of power. (Not shown.)

I have found that by a plying the counterweight 7 7 7 to the bri gespan by means of the compound lever I) said counterweight acting through the lever member 2 2'2 will create a component acting-substantially at right angles to a right line connect/in the point of pivotal connection of said ism member to the bridge-span with the axis of the trunnions O of said bridge-span, and thus tending to rotate the bridge, which will vary as the load opposed'f thereto varies as the bridge-span moves from closed to open position, or vice versa. It is thus obvious that by the use of a proper counterweight the bridge-span will be exactly counterbalanced in every position opened position.

I claim-- 1. In abridge, the combination tically-swinging bridge-span, of ance therefor, comprising a 0'0 with a verounterbah 1rd iever,

comprising a member pivoted to'a fixed sup-' port, a second member pivoted to saidifirst member at one end and to the shore end of the bridge-span at its other end, the relation being such that said lever members will be substantially parallel; respectively, to-right lines, one passing through the pivot of the bridge-span and the point of pivotal attach ment of said second'l'ever' member to said bridge-span and the other through the pivot of said bridge spxan and the point of pivotal attachment of said first lever member to its an port, and a counterweight applied to said first lever member.

from its closed to its fully 2. In a bridge, the combination with a vertically-swinging bridge, of a counterbalance therefor, comprising a compound lever comprising a member pivoted to a fixed support above the .pivot of said bridge-span, a second member pivoted to said first member at one end and to the shore end of the bridge-span at its other end, the relation being such that said lever members will be substantially parallel, respectively, to right lines, one passing through the pivot of the bridge-span and the oint of pivotal attachment of said second ever member to said bridge-span and the other through the pivot of said bridge-span and the point of pivotal attachment of said first lever member to its support, and a counterweight applied to said first lever member.

3. In a bridge, the combination with a vertically-swinging bridge-span, of a counterbalance therefor, comprising a compound lever comprising a member pivoted to a fixed suport diagonally above the pivot of said bridge-span, a second member pivoted to said first member at one end and to the shore end of the bridge-span at its other end, the relation being such that said lever members will be substantially parallel, respectively, to right lines, one passing through the pivot of the bridge-span and the (point of pivotal attachment of said secon lever member to said bridge-span and the other through the pivot of said bridge-span and the point of pivotal attachment-of said first lever member to its support, and a counterweight applied to said first lever member.

4. In a bridge, the combination with a vertically-swinging bridge-span, of a counterbalance therefor, comprising a compound lever, comprising a member pivoted to a fixed support, a second member pivoted to said first member at one end and to the shore end of the bridge-span at its other end, the relation being such that said lever members will be substantially parallel, res ectively, to right lines, one passing-throug 1 the pivot of the bridge-span and the point of pivotal attachment of said second lever member to said bridge-span andthe other through the pivot of said bridge-span and the point of pivotal attachment of said first lever member to its sup ort, a counterweight, a support provided wit guides for said counterweight and a strut connecting said counterweight with said first lever member.

5. In a bridge, the combination with a vertically-swinging bridge-span, of a counterbalance therefor, comprising a compound lever, comprising a member pivoted to a fixed support, a second member pivoted to said first member at one end and to the shore end of the bridge-span at its other end, the relation being such that said lever members will be substantially parallel, res ectively, to right lines, one passing throug the pivot of the bridge-span and the point of pivotal attachment of said second lever member to said bridge-span and the other through the pivot of said bridge-span and the point of pivotal attachment of said first lever member to its support, a counterweight, a support provided with guides, a head or carriagemovably fitted to said guides, a strut pivotall. connected to said head and to said first lever member and a counterweight carried on said. strut.

6. The combination of a brid e-span comprising two trusses, supports t erefor comprising only members located outside of the trusses of said bridge-span-and means for pivoting said bridge-span to said su ports comprising trunnions secured in one t ereof which rotatably engage suitable bearings in the other, said bridge-span comprising a shore end which projects beyond the pivotal oint thereof and is braced transversely beow its pivotal point. 7

7. The combination of a bridge-span comprising two trusses, supports therefor comprising only members located outside of the trusses of said bridge-span and means for pivoting said bridge-span to said supports comprising trunnions secured against rotation in said supports and which engage suitable bearings on said bridge-span,sa1d bridgespan com rising a shore end-which projects beyond t e pivotal point thereof and is braced transversely below its ivotal point.

In testimony that I claim t e foregoing as my invention I affix my signature, in presence of two subscribing witnesses, this 30th day of January, A. D. 1906.

FREDRIK G. BORG. Witnesses:

K. 'A. CosTELLo, E. M. KLATCHER. 

